Roselaar & Prins (2000) indicated there were two syntypes of Bombycivora japonica von Siebold, 1824; a 1st-winter female in the collection of the Zoologisch Museum Amsterdam, while the other, a male, was considered lost. However, in a letter to Temminck, von Siebold made clear that the species was described on the basis of one specimen. His description is clearly taken from a 1st-year male. Temminck (1828) described Bombicilla phoenicoptera based on the same ZMA specimen and an adult female specimen in the National Museum of Natural History in Leiden, collected by von Siebold, which arrived in Leiden in 1827. The latter species is a synonym of the former. Because it is a female, the ZMA specimen cannot be the holotype of Bombycivora japonica. However, a 1st-year male that arrived in Leiden in 1829 answers to von Siebold's description and this might be the holotype of B. japonica.